Repeated plasma current induced by potential fluctuation in atmospheric pressure non-thermal-equilibrium plasma jet

When a plasma irradiates a metal object, a plasma current flows. Plasma currents in the forward and reverse directions, flowing from a powered electrode, for plasma generation, to the metal object, are repeatedly generated. The first plasma current is generated by the applied voltage of the powered electrode. The metal object onto which the plasma flows is charged by the plasma, and the potential of the metal object increases. The potential of the powered electrode follows the time variation of the applied voltage from the AC power supply. Consequently, when the potential time fluctuation of the powered electrode and the potential of the metal object are balanced, a plasma current in the reverse direction is generated. Because the residual charge on the metal object is determined by the dynamic pressure balance due to the potential time fluctuation between the powered electrode and the metal object, the plasma charge flowing in the reverse direction of the electrode can be determined.